During cell cycle of a ciliate Tetrahymena thermophila the divisions of micro- and macronucleus, cortical morphogenesis and cytokinesis are temporarily coordinated. Cortical morphogenesis begins with proliferation of the new ciliary basal bodies (BBs) within meridional cortical rows of ciliary BBs, and with the local proliferation of BBs, which form the new oral apparatus (OA2), positioned subequatorialy and destined for prospective posterior daughter cell (opisthe). Prior to cytokinesis, two prospective daughter cells are of equal size and show metamery of their cortical patterns. We studied effects of 20 μM roscovitine (an inhibitor of several cyclin-dependent kinases) on the cell cycle progression of T. thermophila. We showed that roscovitine delayed cell division, delayed or arrested macronuclear division and induced increase of cell size and the number of BBs in the cortical rows. The increase in the number of BBs in cortical rows induced cell elongation which was proportional to the increase in cell surface area. There was uncoupling between this BBs proliferation which is continued during prolonged cell cycle and delayed cytokinesis, what resulted in topological alteration of the respective positions of the OA2 and of the contractile vacuole pores (CVPs). In roscovitine treated cells, the new OA2 was positioned subequatorialy, but the fission zone was shifted posterior to the equatorial plane of the cell and positioned across and in the extreme cases behind of the new OA2. This resulted in the formation of a large proter and small size opisthe. The roscovitine treatment induced a formation of a plethora of phenotypes of postdividing cells. We found that irrespective of changes in divisional morphogenesis induced by roscovitine treatment, all mature BBs were associated with the cdc14-like phosphatase. Taken together all these data indicate that during cell cycle of T. thermophila the normal morphology of the daughter cells depends on the proper division of micro- and macronucleus and on temporal control of BBs proliferation along the longitudinal rows, during OA2 stomatogenesis and during selection of BBs involved in differentiation of apical BBs (couplets) and cell division.

Zoelucasa sablensis n. gen et n. sp. is a small heterotrophic fl agellate housed within a pyriform lorica of relatively large imbricate, circular siliceous scales. It was found in near-shore benthic sand/seawater samples of both the Pacific and Atlantic Oceans (west and east coasts of Canada; salinity = 32–33 ppt). The median length and width of the lorica was 18 and 11 μm, respectively (n = 29). This taxon lacks chloroplasts and swims with a slow zig-zag motion controlled by a short (5–7 μm long), anteriorly-directed flagellum and a longer trailing flagellum, 15–20 μm in length. Its classification within the phylum Cercozoa (most likely, Class Imbricatea) is tentative, as there are no known morphological homologues (discoidal, overlapping siliceous plate-scales forming a test or lorica enclosing a heterotrophic flagellate). Further study of cultured and wild material, including a search for other possible non-flagellate (e.g. amoeboid?) life history stages, TEM examination of cell sections, and rDNA sequencing will most certainly provide more opportunities for a justifi able classifi cation, possibly including a new Order.

This is the first study of free-living heterotrophic flagellates in intertidal sediments of Saros Bay, Aegean Sea (Turkey). In order to contribute to an understanding of the geographic distribution of free-living marine heterotrophic flagellates, we investigated the diversity of heterotrophic flagellates occurring in the bay from 25th June 2010 to 10th October 2010. Thirty eight species from 30 genera of heterotrophic flagellates and one unidentifi ed taxon are reported with uninterpreted records based on light-microscopy. The records consist of one apusomonad, one cercomonad, two choanofl agellates, two cryptomonads, 12 euglenids, one heteroloboseid, one kathablepharid, three kinetoplastids, six stramenopiles, two thaumatomonads and seven of uncertain affinities. All of the morphospecies described here was previously reported elsewhere and appear to be cosmopolitan.

We investigate for the first time the species composition and community structure of lobose thecamoebians (Arcellinida) inhabiting an unpopulated and pristine island from the southeastern Pacific. Results revealed low alpha diversity and a high proportion of cosmopolitan species. One genus, four species and two subspecies were identified for the first time for southwestern South America. Further, four morphotypes were not identifi ed to species level, and one could not be identifi ed to species or genera level. They are probably endemics of this poorly studied and remote zone. These results were consistent with the moderate endemicity hypothesis of microbial biogeography. We hypothesized that the low diversity of species recorded on the island is due to selective colonization-extinction dynamics, processes that determines the low species richness of insular macro-organisms. However, this hypothesis needs to be evaluated in the future. Statistical analysis showed that testate amoebae were distributed in two discrete communities in the island. The first consisted of organisms inhabiting habitats located within a forest and the second by organisms inhabiting habitats located outside the forest. The suggested primary factor differentiating these both communities was the availability of appropriate habitat for the different species of testate amoebae.
 

Understanding the spatial distribution of soil protozoa under the snow cover is important for estimation of ecosystem responses to climate change and interpretation of results of field experiments. This work explores spatial patterns of soil testate amoebae under the snow cover at the plot scale (the range of metres) in arctic tundra (Qeqertarsuaq/Disko Island, West Greenland). To explain spatial patterns in abundance, species diversity and assemblage composition of testate amoebae, we measured microtopography, snow depth and substrate density. The results indicate that the abundance of active testate amoebae under the snow cover was quite low. The empty shell assemblage was characterised by the presence of linear spatial trends in the species composition across the site, whereas no patterns were detected within the plot. The distribution of the abundance and the species diversity were unstructured. The linear trends in the species composition corresponded to the site microtopography and were controlled by the topography-related soil moisture. Snow depth also affected the linear trends presumably by controlling soil temperatures. Overall, the results suggest that population processes do not generate spatial patterns in protozoan assemblages at the plot scale so that protozoan distribution can be considered random at macroscopically homogeneous plots.

Ostrinia nubilalis populations from Slovakia, Romania, Austria, Serbia and Germany were collected in the autumn when the insects were in the larval stage. These insects were then established as laboratory populations. The number of pupae and adults that developed was always higher in the Nosema pyrausta non-inoculated (uninfected) populations than in the populations treated by the pathogen N. pyrausta (infected). Significant differences were also found among the populations from different countries. Infected females laid significantly fewer eggs compared to uninfected females. The average time for pupal eclosion or adult emergence was not signifi cantly different between the uninfected and infected populations of O. nubilalis. However, it was found that the infected females laid their eggs significantly sooner as compared to the uninfected females (37.383 days compared to 40.089 days). Under the same conditions, populations from colder regions developed faster than those from warmer regions. The place of origin of the population did not significantly influence larval weight, larval length or pupal weight. However, larvae infected with N. pyrausta spores had signifi cantly lower weight (average 0.0797 g) than uninfected larvae (0.0901 g). With regard to pupal weight, the difference between the infected and uninfected individuals was not signifi cant. It was confi rmed that N. pyrausta from one European country can infect and infl uence host larvae originating in other countries. Although there have been several statistically significant interactions with regard to the country of origin and N. pyrausta infection, it was not believed that N. pyrausta from one country would have specific effects on the mortality, developmental rate and larval or pupal weight of O. nubilalis populations from different countries.

This paper deals with the morphology and life history of two new species of septate greganines (Apicomplexa: Conoidasida: Gregarinidae) of the genus Unilobus Théodoridès, Desportes & Jolivet, 1984, obtained from two tenebrionid beetles of West Bengal, India.These are Unilobus gonocephali n. sp. from Gonocephalum sp. (Insecta: Coleoptera: Tenebrionidae) and Unilobus scleroni n. sp. from Scleron irregulate (Insecta: Coleoptera: Tenebrionidae). Total length of U. gonocephali varies from 200–467 μm. Gametocysts spherical, 410 μm in average diameter, dehisces through 7–9 sporoducts. U. scleroni is comparatively smaller, total length varies from 61–232 μm. Gametocyst spherical with average diameter 350 μm, dehices through 10 to 12 sporoducts. The two new species share traits which define the genus such as the absence of epimerite, expanded protomerite and late association. These two described species are not only different from the previously described species, but also oocysts (= spores) entirely different from each other in characters like measurements, number of sporoduct and in host range. This communication also confi rmed the validity of the genus Unilobus Théodoridès, Desportes & Jolivet, 1984 and its placement under the family Gregarinidae Labbé, 1899.